Is Science on the Scent of Predicting Early Alzheimer's?
Aug. 28, 2000 -- Is it possible the nose knows what doctors don't about Alzheimer's disease? At one time or another, many people have misplaced their keys or forgotten to show up for a dental appointment. But are they just getting older, or could it be an early sign of Alzheimer's disease? It's a simple question with a difficult answer, because currently there is no test to make the prediction. But now a scratch-and-sniff test may provide a simple answer.
One in 10 people over age 65 have Alzheimer's disease, as do nearly half of people over age 85. The disease causes brain cells to die, affecting memory, judgment, and eventually self-care. But many elderly people with mild forgetfulness never get worse, and some have a condition called mild cognitive (or thinking) impairment, in which memory problems are a little worse than those seen in normal aging, but they do not have the confusion or disability seen in Alzheimer's patients.
The biggest problem facing physicians who treat Alzheimer's disease, at the moment, is determining who really has Alzheimer's disease. Neuropsychologist Elisabeth Koss, PhD, explains that there is not much that can be done at present to confirm the diagnosis of early Alzheimer's disease, as current tests are still considered experimental.
Now, researchers from Columbia University in New York City report in the September issue of the American Journal of Psychiatry that a simple scratch-and-sniff test may hold the key. The researchers suggest that difficulty recognizing common odors may identify those at risk for Alzheimer's disease, especially when they are unaware that their sense of smell is impaired.
"The hope is that a simple test like this could identify those patients destined to develop Alzheimer's, so that they could be given experimental medications early in the disease, when they might be of most benefit," study author D. P. Devanand, MD, a professor of clinical psychiatry at Columbia University, tells WebMD.
"Not everyone who has [smell problems] will turn out to get Alzheimer's disease," says Koss, who is assistant director of the Alzheimer's Disease Center Program at the National Institutes of Aging, which is one of the funding sources for this research.